User Tag List

Results 1 to 9 of 9
  1. #1
    Fireside Member
    Join Date
    Apr 2015
    Location
    Pittsburgh Pa
    Posts
    79
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Unhappy Run 12V without a battery--good practice?

    We are on shore power but we forgot the battery at home, could that be the issue?

    All the text below was written by howson (Moderator Howard):
    The above was copied from the OP's post in the Plumbing section. I'm curious about this and wanted to discuss it further so to keep the other thread on topic I created this new one.

    Edit: Note the following numbers are wrong--I left them wrong so the subsequent posts make sense.
    I did some research on Grand Design's part page and Megan's 323BHS could have either a 55W, 65W, or 75W converter. Let's assume it is the 75W converter--that's still only a maximum of 6.25 amps, right? (75W/12V=6.25A)

    The converter's primary job is to charge the battery. The battery's primary job is to power the trailer's 12V systems.

    Am I wrong? Wouldn't it be a good practice for the OP to install the battery and not rely primarily on the converter? (The picture below is the 12V fuses on my 315RLTS. Obviously it is possible to draw way more than 6.25 amps.)

    Click image for larger version. 

Name:	DC Fuses.jpg 
Views:	21 
Size:	94.1 KB 
ID:	19632
    Last edited by howson; 04-27-2019 at 05:22 PM.

  2. #2
    Seasoned Camper
    Join Date
    Oct 2018
    Location
    Eastern Washington
    Posts
    122
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I think those should be amp ratings on the converter (my 2500RL came with a 55A converter), not watts. The converter does both, supplying 12v for DC lights and appliances and charging the battery. Should be no problem even running without a battery and just using the converter for everything. Actually the "converter doing both" isn't 100% accurate as it and the battery are on the same 12v bus basically, so if you're under an extreme load and the converter voltage sags below that of the battery you'd be pulling from the battery. I don't think that condition would ever happen with stock equipment, you'd need a big draw like an inverter.

  3. #3
    King Pin
    Join Date
    Feb 2014
    Posts
    6,521
    Blog Entries
    10
    Mentioned
    41 Post(s)
    Tagged
    1 Thread(s)
    Actually, those are amp readings.

    55 amp converter, 12V * 55 Amps = 660 Watts
    65 amp converter, 12V * 65 Amps = 780 Watts
    75 amp converter, 12V * 75 Amps = 900 Watts

    Jim

  4. #4
    Long Hauler howson's Avatar
    Join Date
    Dec 2017
    Location
    NW Florida
    Posts
    2,816
    Mentioned
    49 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by TucsonJim View Post
    Actually, those are amp readings.

    55 amp converter, 12V * 55 Amps = 660 Watts
    65 amp converter, 12V * 65 Amps = 780 Watts
    75 amp converter, 12V * 75 Amps = 900 Watts

    Jim
    How the heck did I miss that?

    Well, at least one misconception on my part is straightened out. (I thought a battery had to be installed.)

    Thanks to the OP for their indulgence with me using their post for my question.
    2017 Ford F-350 DRW 6.7L Platinum
    2019 315RLTS (purchased 16 Jul 18 from Campers Inn RV in Byron, GA)

  5. #5
    Fireside Member
    Join Date
    Apr 2015
    Location
    Pittsburgh Pa
    Posts
    79
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by howson View Post
    Thanks to the OP for their indulgence with me using their post for my question.
    Thank you for taking the time to ask it. Now we know! The battery will still be coming up with us next time as it does come in handy when the power goes out.
    2015 Reflection 323BHS
    No tow vehicle at the moment :(
    Who uses our RV?
    - One old dog, blind and selectively deaf
    - A wonderful granddaughter that just loves the bunkhouse
    - A husband who is just as sad as myself to leave the RV as I am

  6. #6
    Site Sponsor Cate&Rob's Avatar
    Join Date
    Jul 2014
    Posts
    8,880
    Mentioned
    85 Post(s)
    Tagged
    0 Thread(s)
    Megan . . . I know that you are not towing, but it is important for those who do, to remember that a (charged) trailer battery should always be connected, as a key part of the emergency break-away trailer braking system.

    Rob
    Cate & Rob
    2015 Reflection 303RLS

  7. #7
    King Pin
    Join Date
    Feb 2014
    Posts
    6,521
    Blog Entries
    10
    Mentioned
    41 Post(s)
    Tagged
    1 Thread(s)
    In full agreement with Rob. Never tow without a battery connected at all times. The emergency break away system will not activate without a battery.

    But if you are parked, you do not need to have a battery connected.

    Here is a FAQ on the WFCO Page:

    "Q: Does the converter need a battery to operate:

    A: No. The battery works in conjunction with the converter to supply DC power to the RV. A battery is typically only necessary if you do a lot of dry camping or have slide-outs and/or a leveling system."

    In other words, a large DC draw such as a slide out may take more power than the converter can provide.

    Jim

  8. #8
    Seasoned Camper 2825Matheny's Avatar
    Join Date
    Mar 2015
    Location
    Full Time - Domicile State is TN
    Posts
    165
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Megan Coriale View Post
    We are on shore power but we forgot the battery at home, could that be the issue?

    All the text below was written by howson (Moderator Howard):
    The above was copied from the OP's post in the Plumbing section. I'm curious about this and wanted to discuss it further so to keep the other thread on topic I created this new one.

    Edit: Note the following numbers are wrong--I left them wrong so the subsequent posts make sense.
    I did some research on Grand Design's part page and Megan's 323BHS could have either a 55W, 65W, or 75W converter. Let's assume it is the 75W converter--that's still only a maximum of 6.25 amps, right? (75W/12V=6.25A)

    The converter's primary job is to charge the battery. The battery's primary job is to power the trailer's 12V systems.

    Am I wrong? Wouldn't it be a good practice for the OP to install the battery and not rely primarily on the converter? (The picture below is the 12V fuses on my 315RLTS. Obviously it is possible to draw way more than 6.25 amps.)

    Click image for larger version. 

Name:	DC Fuses.jpg 
Views:	21 
Size:	94.1 KB 
ID:	19632
    "The converters primary job is to charge the batteries" isn't entirely true.
    I have installed two 12-volt power meters to monitor converter performance and load use.
    When connected to shore power and after the battery is charged, all if the 12-volt power consumed by your RV comes from the converter.
    So, most of the time you don't even need a battery.
    The only times you truly need a battery are when towing (for emergency brakes), when operating hydraulics or starting a generator or boondocking (without solar).
    Otherwise, the converter does all the work.

    Sent from my Pixel 3 XL using Tapatalk
    Peggy and Jamey Matheny
    2016 Grand Design Solitude 5th Wheel 369RL Serial #G1104808
    As of 19 April 2019, 792 nights and 23,887 trailer miles.
    2015 Ford F-250 4X4 Super Cab SRW 148" WB 6.7L Powerstroke Diesel

  9. #9
    Long Hauler
    Join Date
    Jun 2018
    Posts
    2,356
    Mentioned
    16 Post(s)
    Tagged
    0 Thread(s)
    I will add to the above, if the draw on the converter is larger than it can handle then the battery is used to supplement.(learned this here). Our last TT did not have LED lights so when a lot of the lights were turned on there we could here the converter fan running because the converter was at peak operation.

    Brian

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

DISCLAIMER:This website is not affiliated with or endorsed by Grand Design RV, LLC or any of its affiliates. This is an independent site.